Mechanical floating head brake



May 23, 1967 H. c. SWIFT MECHANICAL FLOATLNG HEAD BRAKE Filed May 12,1965 3 Sheets-Sheet l INVENTQR. f/ar/a z/ 6T J'wz/f y 3, 1967 H. c.SWIFT 3,321,049

MECHANICAL FLOATING HEAD BRAKE Filed May 12, 1965 3 Sheets-Sheet 2INVENTOR. y 0". J .4027 7 y 1967 H. c. SWIFT MECHANICAL FLOATING HEADBRAKE 3 Sheets-Sheet 5 Filed May 12, 1965 INVENTOR. m y 6. J W156 BY g.j 4/.

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United States Patent 3,321,049 MECHANICAL FLOATING HEAD BRAKE Harvey C.Swift, Birmingham, Mich., assignor to Kelsey- Hayes Company, Romulus,Mich, a corporation of Michigan Filed May 12, 1965, Ser. No. 455,279 1Claim. (Cl. 183-73) This invention relates to disk type brakes forvehicle wheels and, more particularly, to a mechanical floating headtype brake for use with brakes of this type, usually as an emergency orparking brake.

One of the objects of this invention is to provide a mechanical brake ofthis type which is self-energizing and thus is more efficient thanconventional types of mechanical brakes.

Another object of the invention is to provide an emergency brake inwhich the braking force is applied to the brake disk by brake shoes ofthe disk brake type.

Another object of the invention is to provide an emergency brake of thistype which may be readily associated with the caliper of conventionalhydraulically operated disk brakes.

Still another object is to provide a brake of this type with a floatingcaliper or housing in which the brake shoes are mounted for manuallyapplying pressure to one of said brake shoes and through the reaction ofthe caliper to apply braking pressure to the opposite bnake shoe.

A further object of this invention is to anchor the brake shoes to astationary part or member by means of angularly disposed converginglinks so that movement of the brake shoes during application of thebrakes, While the ehicle is moving in a forward direction, will cause awedging movement of the brake shoes toward the brake disk, thusresulting in an effective self-energizing action.

Another object of the invention is to provide a combined hydraulicallyactuated brake and a mechanically operated brake which may convenientlybe combined into one compact unit.

Therefore, it is an object of this invention to provide a hydraulicallyoperated disk brake havinga mechanically operated par-king or emergencybrake combined therewith in such a manner that each brake actuatingmechanism may be operated independently of the other and wherein thecombined brakes and actuating means therefor are consolidated andassembled into a unit which may be economically manufactured, quicklyand easily assembled and installed, and in which maintenance costs arereduced to a minimum.

The various objects and advantages, and the novel details ofconstruction of two commercially practical embodiments of the invention,will become more apparent as this description proceeds, especially whenconsidered in connection with the accompanying drawings, in which:

FIGURE 1 is an elevated view of a brake constructed in accordance withthis invention, with the wheel removed;

FIGURE 2 is a top plan view of a portion of FIGURE 1 looking in thedirection of arrow A;

FIGURE 3 is a fragmentary sectional view taken substantially on theplane indicated by line 3-3 in FIG- URE 1;

FIGURE 4 is a fragmentary sectional view taken sub stantially on theplane indicated by line 4-4 in FIG- URE 1;

FIGURE 5 is a fragmental view on line 5-5 of FIG- URE 4;

FIGURE 6 is a detail view taken on line 6-6 in FIG- URE 4;

FIGURE 7 is a view similar to FIGURE 1 of a modified form ofconstruction;

FIGURE 8 is a fragmentary sectional view taken substantially on theplane indicated by line 8-8 in FIG- URE 7; and

FIGURE 9 is a detail section on line 9--9 of FIG- URE 7.

The brake of this invention is shown as being associated with a vehiclewheel having a rim it} and a Wheel body 11 secured to the axle flange 12by means of studs or bolt and nut assemblies 13.

In FIGURES 1 and 2, a manually or mechanically operated hand brake H isshown as being associated with a substantially conventional caliper typehydraulically operated brake B. The essentials of the caliper typehydraulic brake B will first be described, although this part of thebrake construction forms no part of the present invention.

Secured to the axle flange 12 (see FIGURE 3), as for instance by meansof the same stud or bolt and nut assemblies 13, in a brake disk 15. Inthe form of the invention illustrated, the brake disk is formed with apair of spaced walls 15a and 15b.

Enclosing a part only of the braking surface of the brake disk 15 is acaliper-like member 20 in the form of a housing or yoke member. As willbe seen from FIG- URE 3, the sides of the yoke member are spaced onopposite sides of the disk 15 and are shaped to provide opposedcylinders 21 in which the brake shoe operating pistons 22 are disposed.These pistons engage brake shoes 23 and 24, each of which is providedwith a backing plate 25 having a friction lining 26. Each backing plate25, see FIGURE 1, is formed with a pair of cars 27 which engage ledges2-8 on the caliper or housing 20 to slidably support the brake shoes.

The caliper member or housing 20 is mounted on a fixed part 30 of theaxle structure by means of a torque member 31 to which the housing 20 isattached by bolts 32. The torque member 31 is connected to the axle part30 by means of bolts 34.

Each piston 22 is provided with an annular seal 35 which restricts freemovement of the piston and also seals the periphery thereof. Also, aflexible annular boot 36, formed of rubber, canvas, or any othersuitable flexible material, may be provided to close the clearancebetween the pistons 22 and the cylinders 21 to exclude therefrom dust orother foreign material.

Fluid may be introduced into the cylinders 21 behind the pistons 22 bymeans of a fluid pressure inlet 4%). The reference character 41indicates one or more conduits connecting the cylinders 21 on one sideof the device with the cylinders on the other side so that fluid maysimultaneously be admitted to both sets of cylinders. Also, thecylinders are connected by an interior conduit 42 to a bleed opening 43whereby the system may be freed from trapped air.

While one particular form of hydraulically operated brake has beenillustrated and described, it will be apparent as this descriptionproceeds that any desired or preferred type of hydraulic brake may beemployed and associated with the manually or mechanically operated handbrake H.

The subject matter of the present invention consists in providing amechanical floating head type brake which is self-energizing.

As shown in FIGURES 1, 2 and 4, the mechanically operated hand brakecomprises a floating head consisting of a caliper-like member 50straddling a. portion of the brake disk 15. One leg 51 of thecaliper-like member 50 engage brake shoe 52 to actuate this brake shoethrough the reaction of the caliper-like member when the other brakeshoe is manually operated. The manually operated brake shoe is indicatedby the reference character 53. The brake shoe 52 is provided with abacking plate 54 of substantially conventional construction and thebrake shoe 53 is provided with a backing plate 55. The backing plate 55is provided with an annular flange or extension 56 Which extends into anannular recess 57 formed in the caliper-like member 50. Thus, the brakeshoe 53, as well as the brake shoe 52, is capable of movement in atorque direction when the brakes are applied.

While any suitable or preferred mechanical means may be provided foractuating the brake shoe 53, there is shown a brake actuating lever 58which is fixed by a key 59 to a sleeve member 60. The sleeve member 60is provided at one end with an outwardly extending flange 61 which isprovided with a shallow tapered or dish-shaped recess 62 (see FIGUREconstituting part of the cam means for operating brake shoe 53. Thecaliper member 50 is provided with a bore 63 which is closed by a platemember 64 provided with an extension 65, the end face of which confrontsthe flange 61. This confronting face is also provided with a shallowtapered or dish-shaped recess 66; see FIGURE 5. One or more balls 67 aredisposed in the space defined by the combined recesses 62 and 66, sothat upon relative rotation of the sleeve member 60, a thrust to theleft Will be imparted to the sleeve member to actuate the brake shoe 53.When the brake shoe 53 is actuated, the caliper-like member 50 moves, byreaction, to the right, as viewed in FIGURE 4, to apply braking pressureto the brake shoe 52.

The thrust of the sleeve member 60 is imparted to the brake shoe 53through a stud or plug member 68 which is engaged with the bore of thesleeve member 60. This stud or plug member is provided with a head 69provided with a shallow tapered or dish-shaped recess 70 and theconfronting face of the backing plate 55 of the brake shoe 53 isprovided with a similar recess 71. A ball 72 is interposed between thesurfaces of the recesses 70 and '71 so that the thrust on the brake shoe53 is imparted through the ball 72. This permits the brake shoe 53 toshift in a torque direction to the extent allowed by the annular reces57. A threaded pin 73 threaded into the :sleeve member 60 may beprovided to automatically adjust the plug member 68 to initially take upany clearance between the ball 72 land the surfaces of the recesses 70and 71 and to further adjust the position of these parts, if and when itbecomes necessary due to wear thereon.

As illustrated in FIGURES l and 2, the adjacent end of the caliper-likemember 20 is provided with an extension 75 provided with an ear or lug76 for connection to the caliper member 50 of the mechanically operatedhand brake H. To accomplish this connection, the caliper 50 of the handbrake is provided with an ear or extension '77 provided with a slot 78;see FIGURE 2. A bolt 79 extends through the slot 78 and is threaded intoan ear -or extension 76 carried by the extension 75 of the caliper-likemember 20. This allows a floating movement of the caliper 50 so thatwhen the brake shoe 53 is actuated to apply the brakes, the describedreaction of the caliper :50 is permitted so that the leg 51 may applybraking pressure to the brake shoe 52.

In order to rnake the hand brake self-energizing, the backing plates 54and 55 of the brake shoes are provided with extensions 80 and 81,respectively, as shown best in FIGURE 2. The extension 80 is pivotallyconnected as at 82 to the inner end of a link 83 pivotally connected asat 84 to the extension 75 of the caliper-like member 20. In a likemanner, the extension 81 is pivotally connected as at 85 to the innerend of a link 86 pivotally connected as at 87 to the caliper extension75.

As will be seen from FIGURE 2, these links 83 and 86 are angularlydis-posed with respect to one another and diverge [from the pivots 82and 85 to the pivots 84 and 87. During the forward movement of the.vehicle, the brake disk 15 is rotating in the direction of arrow A,FIGURE 2. The torque movement imparted to the brake shoes 52 and 53causes the pivots 82 and 85 to move to the left, as viewed in FIGURE 2,and due th di ing angular arrangement of the links 83 and 86, a wedgingaction results which acts to force the brake shoes into firmerengagement with the brake disk 15. During this movement, the pivots 82and tend to move toward the brake disk 15 in the direction of the arrowsB in FIGURE 2. This renders the brakes self-energizing, as will beapparent.

In order to automatically adjust the brake shoes when the hand brake isapplied, the threaded pin 73 is adjusted to adjust a plug member whenthe brake actuating lever 58 is actuated. This means comprises a dog orpawl 75a secured to the lever 58 adapted to engage an abutment typetooth 73a on the head 73b of the pin 73. Thus, when the lever 58 isactuated, the pawl 75a will engage one of said teeth 73a tending torotate the pin 73. If the pin 73 is rotated one tooth space, a tooth 73aclears a stop member 64a. secured to the plate member 64 to hold the pin73 in its adjusted position to take up any clearance on the head 69 andthe space between the surfaces 70 and 71 and the ball 72 due to wear onthe brake linings.

In FIGURES 7, 8 and 9, a modification is illustrated in which theconventional hydraulically operated caliper type brake B is eliminatedand a combined hydraulically and manually operated brake device C isemployed. This device C is connected by links similar to links 83 and 86to an anchor member 90 which straddles the brake disk 15 and is securedby a bracket 91 and a bolt 92 to a stationary part 93 of the axle andhub structure of the wheel. Also, the links 83 and 86 function in thesame manner as previously described to render the brake selfenergizing.

As shown in FIGURE 8, a hydraulic brake actuating means is combined withthe manually operated means and so constructed that the combinedhydraulically actuated brake and the mechanically actuated brake may beassociated into one compact unit.

In this modified construction, a caliper member 95 is secured to a fixedpart 30a of the axle structure by bolts 96. In this form ofconsrt-uction, the caliper member 95 opposite the mechanical brakeoperating means, is formed with a cylinder 97 adapted to slidablyreceive a brake shoe operating piston 98 which engages the adjacentbrake shoe 52a. The cylinder 97 is connected by a fluid pressure conduit99 to a source of fluid under pressure 50 as to actuate the piston 98.The reference character 99a indicates a bleed opening. The piston 98 ishollow and its inner wall is provided with a plurality of abutment-typethreads or teeth 100. Secured within the cylinder 97 is a collet orsubstantially sleeve-like member 101 which extends into the interior ofthe piston 98. The collet is provided with a head 102 with which a snapring 103 engages to secure the collet in place. As shown in FIGURE 9,the collet is formed with a plurality of axially extending,circumferentially spaced arms 104, each of which is provided withmatching threads or teeth 105 which are adapted to engage the threads orteeth on the piston 98. If the brake lining on brake shoe 52a has becomeWorn sufliciently so that the piston 98 moves more than one tooth spacerelative to the fixed collet 101, the teeth on the piston engage thenext tooth space on the collet arms 104 and will be held in this newposition to compensate for the wear on the brake shoe. As the pistonmoves in applying the brakes, the arms 104 are forced radially inwardlyso that the interengaging teeth may clear one another.

In this modified form of construction, the brake shoes 52a and 53,FIGURE 8, are provided with extensions (not shown) similar to theextensions 80 and 81 (FIGURE 2) which are connected by links similar tolinks 83 and 86 to the anchor member 90. The torque movement imparted tothe brake shoes 52a and 53 causes a movement of the links toward oneanother resulting in a wedging action which acts to force the brakeshoes into firmer engagement with the brake disk to render the brakeself-energizing in the manner previously described.

The application of the brakes by either the mechanical means or thehydraulic means actuates the adjacent brake shoe and through thereaction of the caliper-like member 95 actu-ates the other brake shoe.

The means for mechanically actuating the brake includes a lever 158which is secured by a pin 160 to a pluglike member 161 rotatably mountedin the plate member 164. The plate member 164 is provided with anextension 165, the end face of which confronts the front face of aflange 166 on the plug. These confronting faces are provided with camrecesses in which balls 167 are disposed. Therefore, relative rotationof the plug member 161 and the plate member 164 imparts a thrust to theleft to actuate the brake shoe 53. The plug-like member 161 is providedwith a head 170 provided with a cam recess 170a and the confronting face55 of the backing plate of brake shoe 53 is provided with a similarrecess 171. A ball 172 is intel-posed between the surfaces of therecesses 170a and 171 so that the thrust on the brake shoe 53 isimparted through the ball 172. This permits the brake shoe 53 to shiftin a torque direction to the extent allowed by the annular recess 57.

From the foregoing, it will be apparent that there is provided aself-energizing, manual-1y operated mechanical brake which may be usedas an emergency or parking brake. This brake unit may be associated withthe conventional type hydraulically operated caliper brake, or it may becombined as a unit with a hydraulically actuated 'brake, as shown bestin FIGURE 7.

The objects and advantages of the invention are accomplished byconstructions which are so reduced in the number and character of theircomponent parts as to approach the ultimate in structural simplicity tothereby create an economy in the manufacture, installation andmaintenance cos-ts of the brake.

While two commercially practical embodiments of the invention have beendescribed and illustrated herein somewhat in detail, it will beunderstood that various changes may :be made as may come within thepurview of the accompanying claim.

What is claimed is:

In a mechanical floating head type brake for wheels having a brake diskrotatable with the wheel and a fixed support, that improvement whichcomprises a caliper-like member straddling a portion of the brake disk,means supporting said caliper on the fixed support for axial movementrelative to the brake disk, a pair of pivoted links pivotally connectedto the fixed support on opposite sides of the disk and projecting in agenerally circumferential direction, a pair of brake shoes, each of saidbrake shoes being supported by one of said links within said caliper,actuating means carried by said caliper for directly motivating one ofsaid shoes against the disk and through reaction on said caliperproducing movement of the other brake shoe against the disk, andautomatically adjustable means between said caliper and said actuatingmeans for taking up clearance between said brake shoes and the disk,said brake shoes being unconnected to the caliper and said actuatingmeans to permit said caliper and actuating means to engage said shoes invarying locations depending upon the wear of said shoes.

References Cited by the Examiner UNITED STATES PATENTS 2,73 6,396 2/19'56 Rasmussen et a1 188196 2,820,530 1/1958 Chouings et al 188-496 X2,901,059 8/1959 Stacy 18873 2,946,408 7/ 1960 Peras 188-73 3,155,19511/1964 Brawerman 18873 3,169,608 2/1965 Press et a1 188-496 X 3,207,2679/1965 Beuchle et al. 188--73 3,243,016 3/1966 Swift 188-73 FOREIGNPATENTS 616,746 3/1961 Canada. 1,279,344 11/ 1961 France. 1,002,208 2/1957 Germany.

806,919 1/1959 Great Britain.

962,425 7/1964 Great Britain.

MILTON BUCHLER, Primary Examiner.

G. E, HALVOSA, Assistant Examiner,

